The Municipality of Kea, also known as Tzia, is an island municipality with 2,417 inhabitants. It is located in the western part of the Aegean Sea and forms part of the Cyclades island chain. Covering a total area of 148,926 km², it consists of two islands, Kea and Makronisos. Only Kea is inhabited, whilst Makronisos is considered a historical monument of the Greek civil war era, as it was used as a prison island. Kea has a number of features - including the Agios Nikolaos harbour, which is one of the biggest natural harbours in Europe - that make it a popular tourist destination for sailing, scuba diving, and hiking. The southeastern part of the island is also included in the European Network of Natural Protected Areas, NATURA 2000.